Impeller for centrifugal compressors and the like



A. A. BROOKS. IMPELLER FOR CENTRIFUGAL COMPRESSORS AND THE LIKE.

APPLICATION FILED SEPT- 2, I920.

Patented Aug. 22, 1922.

UNITED stares earanrcranes.

ALFRED A. BROOKS, OF SWAMPSCOTT, ll/IASSACEUSETTS. ASSIGNOR TO GENERAL ELECTRIC COMPANY, A COORATION OF NEW Y0.

IIMPELLER FOR CENTRIF'UGAL COILI'JPRESSORS AND THE LIKE.

eases a.

To all whom it may concern:

Be it known that I, ALFRED a citizen of the United States, residing at Swampscott. county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Impellers for Centrifugal Compressors and the like, of

A. BROOKS,

which the following is a specification.

' verse sectional view of a part of an impeller.

vibrations. v

An impeller embodying my invention may In the;

Referring to the drawing, 5 indicates a shaft on which is mounted an impeller comprising a hub 6, inlet vanes 7 and impeller vanes or blades 8.

l\ ow, according to my invention, I make the impeller vanesor blades 8 of flexible material, the blades being so flexible that they are very limber and offer practically no resistance to bending under inertia forces, centrifugal forces or air forces. By this arrangement the'blades may wave and flutter without any appreciable stress being produced in them and they are not crack due to fatigue induced by repeat-ed be constructed in various ways. present instance I have shown spacing members 9 fastened to hub 6 between the blades, the inlet vanes 7 are shown as being formed integral with such spacing members, but they may be formed-separate therefrom and suitably attached thereto. The impeller as shown rotates in the direction of the arrow in Fig. 1 y and spacing members 9 have straight, radially extending rear faces 10 and curved forward faces 11. The inner ends of vanes8 may extend under spacing members 9 as indicated at 12 and the spacing members and blades are then fastened Specification of Letters Patent.

likely to blades, said blades offering Patented Aug. 22, 1922.

Application filed September%, 1920. Serial No. 407,675.

to hub 6 by bolts 13. This gives a firm anchoring for the blades.

When the impeller is not rotating the blades stand out radially as shown in the dotted lines in Fig. 1. They offer little resistance to bending, however, and when the impeller is starting up they will bend down over the curved faces 11 as shown in full lines in Fig. 1, thereby offering little resistance to starting. -When the speed comes up to normal. however. the blades will be held out radially as shown in the dotted lines in Fig. 1 by centrifugal force and the impeller will operate in the usual manner. The curved faces llhave a radius such that the blades may be bent around them without taking a permanent set or without exceeding the safe working stress for the material.

It is to be noted that when in operation the blades are entirely unsupported. being held radial by. centrifugal force.

In addition to the advantages already pointed out, an impeller embodyin my invention has also the advantages t at it is light'in weight and-can be manufactured at a low cost.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus is only illustrative and that theinvention may be carried out by other means.

What I claim as new, and desire to secure by Letters Patent of the United States. is: i

1. Ina centrifugal compressor, the combination of a shaft, a hub thereon, thin, flexible blades carried by said hub, and trance vanes for directing fluid to be pumped to said blades.

2. An impeller having a hub and blades connected thereto. characterited by the fact that the blades are so flexible they afford little resistance'to bending and when starting up they will bend around the hub' so their ends lie in a circle of smaller diameter to reduce the starting resistance.

3. In a centrifugal compressor, an impellerhaving thin, flexible. radially extending little resistance to bending whereby they may flutter without appreciable stresses being produced in them and whereby when starting the blades may bend to reduce the starting resistance, and spacing members between the blades having curved faces over which the blades may bend when the impeller is starting.

4. In a centrifugal compressor, an impel I lerhaving thin, flexible, radially extending blades, said blades offering little resistance to bending whereby they may flutter without appreciable stresses being produced in them and whereby when starting the blades may bend to reduce the starting resistanw, spacing members between the blades having curved faces over which the blades may ALFRED A. BROOKS. 

